Twice pegged back in Belgrade, the Serbs eventually ended a 13-match unbeaten run in qualification matches by the resolute Austrians thanks to an intervention by man-of-the-match Tadic.
Ireland will next face a wounded Austria in Vienna on November 11, the same day Serbia travel to Wales in another potentially pivotal encounter as the route to Russia takes flight.
A frenetic first-half summed up the best and worst of Serbia. Rampant in attack, they still were easily exposed in defence, often by their own mistakes.
Similar to their draw against Ireland, Serbia’s front three caused havoc to their visitors. Filip Kostic’s movement was a menace for the Austrians, the balance of Tadic was a joy to watch, while Mitrovic displayed a finishing touch belying his measly return of just four goals in his previous 23 international appearances.
Belgrade’s Red Star Stadium was slightly more populated than Ireland’s visit last month but the half-full arena was soon brought to life by Serbia’s explosive start.
Mitrovic signalled his intent after just six minutes
when applying a first-time finish to Tadic’s cut-back after Austria were caught square from Kostic’s flick-on.
But Austria were soon gifted an equaliser.
Stefan Mitrovic allowed Florian Klein’s right-wing cross bobble off his foot on 15 minutes straight to Marcel Sabitzer who rocketed a low shot beyond goalkeeper Vladimir Stojkovi´c from 10 yards.
Serbia regain the lead on 23 minutes following another incisive attack down the right.
Mitrovic sprayed a pass wide to Tadic and timed his run into the box perfectly to head home the Southampton man’s pinpoint cross for his second of the night.
Seven minutes after the restart, Marko Arnautovic skimmed the post with a header but made a more telling impact by setting up the second leveller of the night on 55 minutes. The Stoke City man wriggled through a clutch of defenders to get a shot on goal and, though Ozcan saved, Janko followed up to tap in his 28th international goal.
Roared on by the boisterous home support, Serbia responded. Mitrovic almost had his hat-trick on the hour only for a good save but Tadic made no mistake when drilling a low half-volley home following Aleksander Kolarov’s pass from the left.
By that stage, Austria had lost two of their mainstays, Aleksandar Dragovic and captain Julian Baumgartlinger. Ireland can only hope their injuries rule them out of the next game in four weeks’ time.
Stojkovi´c; Ivanovic, S Mitrovic, Nastasic; Rukavina (Maksimovic 90), Milivojevic, Fejsa, Kolarov; Tadic, A Mitrovic (Gudelj 77), Kostic (Katai 65).
Ozcan; Klein, Dragovic (Prodl 71), Hinteregger, Wimmer; Baumgartlinger (Ilsanker 58), Alaba; Sabitzer, Junuzovic (Schopf 64), Arnautovic; Janko.
Jonas Eriksson (SWE).